1. Technical Field
This disclosure generally relates to autonomously deployable human interface controls (e.g., push buttons, knobs, dials, switches, handles, etc.), and more particularly, to selectively deployed and stowed interface controls comprising an active material actuator, and further comprising an active material actuator utilizing a bi-stable structure for added stroke length, and/or an active material actuator having intrinsic sensing capability.
2. Background Art
Mechanically deployed and stowed interface controls, such as push buttons, have been developed to provide a more facilely and ergonomically engaged component when manipulation is desired, and a more visually pleasing (e.g., concealed) presentment when not in use. Conventional methods of shifting controls include manual and mechanical drives, electrical motors, and generating fluid pressure differentials adjacent the structure using vacuums, pumps, and controlled valves. Concernedly, however, these methods often require extraneous labor, inefficient energy input, additional moving parts, complex peripheral sub-systems, and the increased packaging requirements associated therewith.
Active material actuators have been developed for a variety of autonomous functions, but typically present an available stroke directly limited by the active material element. Mechanically advantageous transmissions and other measures have been used to magnify either the force or displacement produced by the element; however, they typically require external mechanical components to create leverage, hold their positions, reset, and protect the actuator wire from excessive loads.